Students map spills over recharge zone

Updated 12:52 am, Monday, November 26, 2012

Undergraduate students at Texas State University have mapped the location of 1,688 sewage spills.

Undergraduate students at Texas State University have mapped the location of 1,688 sewage spills.

Photo: Mike Fisher

Students map spills over recharge zone

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A new interactive map created by students at Texas State University shows where sewer line breaks and overflows have dumped sewage over the recharge zone of the Edwards Aquifer in Bexar County since 2004.

The spills totaled more than 809,000 gallons in the past eight years.

For the students, making the map was a chance to apply the skills they learned in school to a real-word situation. For the San Antonio Water System and its ratepayers, the map is a reminder of what may become a very expensive problem.

“It was really an eye-opening project,” said Mark Wilson, one of the students. “Once you put it on a map, you see how much sewage is going into our aquifer. ... We found a lot of spills that came from the same pump station that would spill every couple years.”

San Antonio depends on the aquifer for its drinking water and has no means of treating what it pumps out of the ground if the Edwards were contaminated.

The city has been on notice by the U.S. Environmental Protection Agency and the U.S. Department of Justice since 2007 that it could be forced to spend more in its sewer system to reduce the number of spills. SAWS estimates those improvements could cost between $250 million and $1 billion.

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“However, the total final costs may significantly exceed SAWS preliminary estimates, and will depend on the course of action ultimately agreed upon between SAWS and EPA/DOJ or ordered by a Federal District Court,” a Q&A on SAWS' website states.

The students made the map while working with the Greater Edwards Aquifer Alliance, which advocates against SAWS building more sewer lines over the recharge zone to limit the number of residents living over the sensitive feature and causing more pollution.

“The fewer people you have producing sewage on the recharge zone, the safer you are going to be,” said Annalisa Peace, executive director of GEAA.

SAWS points out that only a small percentage of sewage escapes its sewer lines.

“We do a heck of a good job of treating what we collect,” SAWS spokeswoman Anne Hayden said.

But the federal standard to protect public health is no leaks or spills, and the EPA and DOJ have forced cities across the country to invest billions in their systems to reduce spills. Consequently, those cities — from Honolulu to Kansas City — have had to double or quadruple their rates.